In a conventional data acquisition system, the function and data flow of event builder and trigger processor are fixed, and there are possibilities of wasting resouces or performance bottleneck depending on the accelerator condition. The purpose of this study is to optimize the usage of the processors and the data flow dynamically by a real time monitoring of the processor load and the data flow rate. In the first year, the monitoring mechanism was developed using a test bench system consisting of 25 PC servers connected via a large GbE switch. The mechanism was realized utilizing Network Shared Memory(NSM) used for the Belle experiment and it was succeeded to make it work. The transfer speed between nodes was also measured using a GRID software called MICH-G2 and was confirmed to be more than 60MB/sec.In the second year, the development of the optimization mechanism of processor utilization and data flow was done. A dynamic change of processing function on a processor was realized by
… Moremodularizing the processing software and replacing them using a dynamic link with the data acquisition framework. Together with a use of large ring buffers and socket connections implemented on each processing node, it was succeeded to change data flow path and/or processing function on a node without interrupting the data acquisition. As the last step, an algorithms to optimize system-wide performance was trying to be developed, however, we have not yet succeeded to develop the mechanism satisfying the real usage in the data acquisition system. A massive switch of the data flow path and processing software is observed to happen at some boundary during a gradual change in the data flow rate, resulting in a waste of resources. Sometimes a short stop of the data acquisition is observed during the switching. Therefore, we need to continue the effort to improve the optimization algorithm with some new technology like the neural-net.The mechanism developed for the monitoring of data flow and processor load was used for the real time reconstruction farm of the Belle experiment and it was reported at the international conference on Computing in High Energy Physics 04. Less